How to Make a Battery out of Coins

Making a battery out of coins is a neat science project that any kid can do at home. The cheapest and easiest way to do this project is using pennies and aluminum foil, however you can substitute the aluminum foil for nickels if you wish. You will get a small trickle of electricity with a single penny and a single piece of aluminum foil, however to really get a noticeable charge, you should probably use 10 or more of each.

Things You'll Need

• Copper pennies
• Paper towel
• Cardboard
• Paper
• Aluminum foil
• Bowl
• Salt
• Scissors
• Tweezers
• Christmas light

Instructions

1. Make supersaturated saltwater in a bowl. Keep adding salt to room temperature water while stirring until no more salt will dissolve.

2. Cut out twenty pieces of paper, paper towel or thin cardboard slightly bigger than a penny. Anything that is porous and will absorb some salt water should work fine, so feel free to use any paper-like material on hand.

3. Cut out 20 pieces of aluminum foil, each about the size of a penny.

4. Soak a piece of paper in salt water and sandwich it between a penny and a piece of aluminum foil. Use tweezers to hold it in the water until it is completely soaked through. Then, place it between a penny and a piece of foil.

5. Keep stacking until you have gone through 20 pieces of each material. Stack in the following order: penny, paper, foil. There should be a penny on one end of the battery and a piece of foil on the other.

6. Wrap your battery. Use a layer of plastic wrap to hold the battery together. Although this step not strictly necessary, the battery tends to fall down if you don't do this. Do not cover the ends.

7. Attach the battery to a Christmas light or other small lamp. Cut a Christmas light out of a strand. Touch one of the wires to one end of the battery and the other to the other end. It should light up.

Tips & Warnings

• Make your stack as straight as possible. The straighter it is, the better the battery will work.

• Try adding more pennies to increase the voltage.

• You can use a voltometer to measure how much energy the battery is producing.

• Don't use really corroded pennies. They will not work as well. In general, the shinier, the better.